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  Display deviceUSPTO Application #: 20070109470Title: Display device Abstract: It is an object of the present invention to provide a liquid crystal display device and the like with high visibility by forming a marker for alignment without increasing an additional step, thereby enabling alignment with high accuracy and reduction in time required for an inspection process in addition to suppressing reduction in yield. A pattern formed over an active matrix substrate which is one of a pair of substrates arranged to be opposed to each other and has a pixel portion is formed as a first marker for alignment, and an opening portion of a light-shielding film formed over an opposite substrate which is the other one of the pair of substrates is formed as a second marker for the alignment. It is to be noted that, by conducting alignment using these markers, alignment of the active matrix substrate and the opposite substrate with high accuracy can be conducted. (end of abstract)
Agent: Cook, Alex, Mcfarron, Manzo, Cummings & Mehler, Ltd. - Chicago, IL, US Inventor: Kunio Hosoya USPTO Applicaton #: 20070109470 - Class: 349110000 (USPTO) The Patent Description & Claims data below is from USPTO Patent Application 20070109470. Brief Patent Description - Full Patent Description - Patent Application Claims
BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to an active matrix liquid crystal display device and the like. [0003] 2. Description of the Related Art [0004] Conventionally, an active matrix liquid crystal display device using an active element such as a thin film transistor (TFT) has been known. In an active matrix liquid crystal display device, pixel density can be heightened. In addition, an active matrix liquid crystal display device is small and lightweight, and consumes low power. Accordingly, products such as a monitor for a personal computer, a liquid crystal television, and a monitor for a car navigation system have been developed as one of flat panel displays in substitution for a CRT. [0005] In a liquid crystal display device, display is conducted in the following manner: a substrate (an active matrix substrate) provided with a pixel portion including a first electrode (a pixel electrode) and the like in addition to a plurality of TFTs and a wiring and a substrate (an opposite substrate) provided with a second electrode (an opposite electrode), a light-shielding film (a black matrix), a colored film (a color filter), and the like are attached to each other; a space between these substrates is filled with a liquid crystal and sealed; and liquid crystal molecules are oriented by an electric field which is applied between the pixel electrode and the opposite electrode to control the amount of light from a light source. [0006] However, it is necessary to conduct alignment with favorable accuracy in attaching the active matrix substrate and the opposite substrate to each other. If the alignment is insufficient, misalignment is caused between the pixel electrode over the active matrix substrate, and the colored film or the light-shielding film over the opposite substrate. This results in reduction in contrast due to light leakage in addition to out of color registration and a blur in an image in displaying, and accordingly, a problem of display with poor visibility is caused. [0007] Concerning this issue, a manufacturing method of a liquid crystal display device is reported as follows: a colored film and a light-shielding film which are conventionally formed over an opposite substrate are formed over an active matrix substrate, and in a step of manufacturing any of a switching element, a colored film, and a light-shielding film, a first marker (an alignment marker) formed using metal or a resin film over the active matrix substrate and a second marker (an alignment marker) formed by coating the opposite substrate with a conductive paint material are compared, whereby alignment with favorable accuracy is possible in attaching the substrates to each other (refer to Patent Document 1: Japanese Published Patent Application No. 2002-350800). [0008] However, the formation of the markers (the first marker and the second marker) for alignment over the active matrix substrate and the opposite substrate, respectively, in an additional step is one of the factors for further reduction in yield in manufacturing a liquid crystal display device and the like through a complicated process. Moreover, a problem that alignment accuracy is lowered and an inspection process for alignment requires much time occurs as a panel is enlarged. SUMMARY OF THE INVENTION [0009] It is an object of the present invention to provide a liquid crystal display device and the like with high visibility by forming a marker for alignment without increasing an additional step, thereby enabling alignment with high accuracy and reduction in time required for an inspection process in addition to suppressing reduction in yield. [0010] One feature of a liquid crystal display device and the like of the present invention is that a pattern formed over an active matrix substrate which is one of a pair of substrates arranged to be opposed to each other and has a pixel portion is formed as a first marker for alignment, and an opening portion of a light-shielding film formed over an opposite substrate which is the other one of the pair of substrates is formed as a second marker for the alignment. By conducting alignment using these markers, alignment of the active matrix substrate and the opposite substrate with high accuracy can be conducted. In addition, a pattern formed in the present invention can be formed using a semiconductor film, an insulating film, a conductive film, or the like formed in a manufacturing process of the active matrix substrate. [0011] A liquid crystal display device in the present invention can be applied in any of a transmissive type, a semi-transmissive type, a low-reflective type (a structure in which the area of a reflective portion is smaller than the area of a transmissive portion), and a reflective type. [0012] Further, the present invention can be applied to a liquid crystal display device using wide viewing angle technique such as an MVA (Multi-domain Vertical Alignment) liquid crystal, a PVA (Patterned Vertical Alignment) liquid crystal, or an ASV (Advanced Super View) liquid crystal, in which alignment of an active matrix substrate and an opposite substrate is important. [0013] A specific structure relating to a liquid crystal display device and the like of the present invention includes at least a pattern formed over one of a pair of substrates arranged to be opposed to each other, and a light-shielding film which is formed over the other one of the pair of substrates and has an opening portion, where the pattern and the opening portion are opposed to each other in the same location. [0014] Another structure relating to a liquid crystal display device and the like of the present invention includes at least a wiring, a thin film transistor, a pixel electrode, and a pattern over one of a pair of substrates arranged to be opposed to each other, and an opposite electrode and a light-shielding film having an opening portion over the other one of the pair of substrates, where the pattern is formed over the wiring, the wiring and the pixel electrode partially overlap, and the pattern and the opening portion are opposed to each other in the same location. [0015] Another structure relating to a liquid crystal display device and the like of the present invention includes at least a wiring, a thin film transistor, a pixel electrode, and a pattern over one of a pair of substrates arranged to be opposed to each other, and an opposite electrode and a light-shielding film having an opening portion over the other one of the pair of substrates, where the pattern is formed over the wiring, part of the pixel electrode overlaps with the wiring in a location in which the pixel electrode does not overlap with the pattern, and the pattern and the opening portion are opposed to each other in the same location. [0016] Another structure relating to a liquid crystal display device and the like of the present invention includes at least a wiring, a thin film transistor, a pixel electrode, and a pattern over one of a pair of substrates arranged to be opposed to each other, and an opposite electrode and a light-shielding film having an opening portion over the other one of the pair of substrates, where the pattern is formed over the wiring, a reflective conductive film is formed over part of the pixel electrode, and the pattern and the opening portion are opposed to each other in the same location. [0017] In each of the above structures, the reflective conductive film is formed so that the area thereof is equal to or less than 50% of the area of the pixel electrode. [0018] In each of the above structures, the pattern is formed using the same semiconductor film as a channel formation region included in the thin film transistor. [0019] In each of the above structures, although the pattern can be formed using a semiconductor film, an insulating film, a conductive film, or the like, the pattern is preferably formed using an amorphous semiconductor or a crystalline semiconductor, containing silicon or silicon-germanium as its main component. [0020] In each of the above structures, the pattern is a marker having any of a cross shape, a quadrangle, and a circle. [0021] In each of the above structures, the opening portion has a similar shape with a similarity ratio of 1 or more with respect to the pattern. [0022] In the present invention, a liquid crystal display device refers to a device using a liquid crystal element, namely an image display device. Further, the following are all included in a liquid crystal display device: a module in which a connector, for example, an FPC (flexible printed circuit), a TAB (tape automated bonding) tape, or a TCP (tape carrier package) is attached to a liquid crystal display panel; a module provided with a printed wiring board at the end of a TAB tape or a TCP; and a module in which an IC (integrated circuit) or a CPU (central processing unit) is directly mounted on a liquid crystal display panel by a COG (chip on glass) method. Continue reading... Full patent description for Display device Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Display device patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Display device or other areas of interest. ### Previous Patent Application: Array substrate having color filter on thin film transistor structure for lcd device and method of fabricating the same Next Patent Application: Liquid crystal display device and method of fabricating the same Industry Class: Liquid crystal cells, elements and systems ### FreshPatents.com Support Thank you for viewing the Display device patent info. IP-related news and info Results in 0.20419 seconds Other interesting Feshpatents.com categories: Medical: Surgery , Surgery(2) , Surgery(3) , Drug , Drug(2) , Prosthesis , Dentistry |
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